Amphitheriidae is a family of Mesozoic mammals restricted to the
Middle Jurassic
The Middle Jurassic is the second Epoch (geology), epoch of the Jurassic Period (geology), Period. It lasted from about 174.1 to 161.5 million years ago. Fossils of land-dwelling animals, such as dinosaurs, from the Middle Jurassic are relativel ...
of
Britain
Britain most often refers to:
* Great Britain, a large island comprising the countries of England, Scotland and Wales
* The United Kingdom of Great Britain and Northern Ireland, a sovereign state in Europe comprising Great Britain and the north-eas ...
, with indeterminate members also possibly known from the equivalently aged
Itat Formation
The Itat Formation (Russian: итатская свита) is a geologic formation in western Siberia. It was deposited in the Bajocian to Bathonian ages of the Middle Jurassic. Dinosaur remains are among the fossils that have been recovered from ...
in Siberia and the
Anoual Formation
The Anoual Formation is a geological formation in the High Atlas of Morocco. It is early Bathonian
In the geologic timescale the Bathonian is an age (geology), age and stage (stratigraphy), stage of the Middle Jurassic. It lasted from approxi ...
of Morocco. They were members of
Cladotheria
Cladotheria is a clade (sometimes ranked as a legion) of mammals. It contains modern therian mammals (marsupials and placentals) and several extinct groups, such as the "dryolestoids", amphitheriids and peramurids. The clade was named in 1975 ...
, more derived than members of
Dryolestida
Dryolestida is an extinct order of mammals, known from the Jurassic and Cretaceous. They are considered basal members of the clade Cladotheria, close to the ancestry of therian mammals. It is also believed that they developed a fully mammalian ...
, and possibly forming a close relationship with
Peramuridae
The family Peramuridae is a family of mammals that lived in the Late Jurassic and Early Cretaceous
The Early Cretaceous (geochronology, geochronological name) or the Lower Cretaceous (chronostratigraphy, chronostratigraphic name) is the earlier ...
.
Amphitheriidae is the only family of the order Amphitheriida.
Classification
Cladogram after Panciroli et al. 2018:
Cladogram after Magallanes et al, 2024:
References
Further reading
*Zofia Kielan-Jaworowska, Richard L. Cifelli, and Zhe-Xi Luo, ''Mammals from the Age of Dinosaurs: Origins, Evolution, and Structure'' (New York: Columbia University Press, 2004), 14,395.
*Close RA., Davis BM., Walsh S., Wolniewicz AS., Friedman M. and Benson RB. 2016. A lower jaw of Palaeoxonodon from the Middle Jurassic of the Isle of Skye, Scotland, sheds new light on the diversity of British stem therians. Palaeontology, 59, 155-169
Cladotheria
Middle Jurassic first appearances
Middle Jurassic extinctions
Taxa named by Richard Owen
{{Jurassic-mammal-stub